M645

I have a Mamiya 645 for about 9-10 months now and enjoy the feel of the camera. I welcome change from my Kiev 88cm with my many ultra leaky backs (only objection to that camera).

My problem with the 645 is a sometimes stiff trigger. It causes me to jerk the camera slightly. Just enough to lose sharpness. What I don't understand is sometimes the trigger is quite smooth. I also have a motorwind unit for it and it suffers the same fate. I was hoping the the consistent trigger motion would solve this.

Is there actually something wrong / worn? Is there an adjustment or something I can do?

There should be one shutter button on the top of the camera and one on the front which is the one that takes a cable release. Also, if I remember correctly the front shutter release has a locking ring. Maybe check that you don't have that partly locked?

Yes, obviously something not quite right. Mine is really light. perhaps it's been knocked at some time and has a very slight bend in it? If all looks straight, I would probably try a little light oil to see if it helps Is there any gunk around the shutter at all?